Light Dependent RXN
Purpose: splits water using the radiant energy of the
sunlight to form oxygen, ATP and NADPH
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Converts and transfers radiant energy into
storage or carrier molecules (ATP or NADPH)
Occurs in thylakoids
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Occurs in stroma of chloroplast.
Reactants: ATP + NADPH + CO2
3 steps
1. Photosynthesis II
2. Electron transport chain
3. Photosynthesis I
Reactant
Radiant Energy
H2O
Dark RXN (Calvin cycle)
Purpose: forms glucose using carbon dioxide
from environment and ATP and NADPH from
light rxn
Products: Glucose
Products
ATP + NADPH + O2
Energy carriers:
1. ATP – Nucleic acid molecule that stores energy
2. NADPH- molecule that carries electrons that fuel the
Calvin cycle
How ATP and NADPH store and carry energy
NADPH- NADP+ picks up electrons from radiant energy
and H+ ions to convert to NADPH
ADP+ -- ATP: H+ ions are placed on a ADP+ to turn into a
ATP storing molecule
Steps of Calvin cycle:
1. 6 CO2 enters cycle from atmosphere and
combined with 6 5-carbon molecules to 12 3carbon molecules
2. Energy from ATP and NADPH electrons
convert the 12 3-carbon molecules into higherenergy forms
3. Two 3-carbon molecules are removed from
the cycle to produce sugars
4. The 10 remaining 3-carbon molecules are
converted back into six 5-carbon molecules used
in next cycle